A survey on uninhabited underwater vehicles (UUV)

ASME Early Career Technical Conference, ASME ECTC, October 2-3, 2009, Tuscaloosa, Alabama, USAThis work presents the initiation of our underwater robotics research which will be focused on underwater vehicle-manipulator systems. Our aim is to build an underwater vehicle with a robotic manipulator which has a robust system and also can compensate itself under the influence of the hydrodynamic effects. In this paper, overview of the existing underwater vehicle systems, thruster designs, their dynamic models and control architectures are given. The purpose and results of the existing methods in underwater robotics are investigated

Underwater Vehicles

For the latest twenty to thirty years, a significant number of AUVs has been created for the solving of wide spectrum of scientific and applied tasks of ocean development and research. For the short time period the AUVs have shown the efficiency at performance of complex search and inspection works and opened a number of new important applications. Initially the information about AUVs had mainly review-advertising character but now more attention is paid to practical achievements, problems and systems technologies. AUVs are losing their prototype status and have become a fully operational, reliable and effective tool and modern multi-purpose AUVs represent the new class of underwater robotic objects with inherent tasks and practical applications, particular features of technology, systems structure and functional properties

The dynamic modelling and development of a controller for a general purpose remotely operated underwater vehicle

A preliminary mathematical model for the UCT SEAHOG Remotely operated underwater vehicle (ROV) is developed, including estimation of the rigid body, hydrodynamic and hydrostatic properties of the robot. A single state thruster model is developed and verified according to real life test data. A closed-loop speed controller is developed for the thruster module using a standard PI scheme and is implemented on an MSP430 microcontroller using software fixed-point algorithms. The complete ROV system is simulated in Simulink® in an open-loop configuration to gain insight into the expected motion from the vehicle. Controllers for depth and heading holding are designed using standard PID linearized control methods with gain scheduling and are then assessed within the complete system in a simulation environment. In addition, upgrades and maintenance are performed on the Power Pod, light and camera modules. Redesign, manufacture and testing of the SEAHOG junction box is performed, including a design solution to connect the tether power and fibre-optic lines at the surface and on the ROV. An extensive overhaul of the SEAHOG GUI is performed, utilising multicore processing architecture in LabVIEW and resulting in a user-orientated interface capable of controlling and monitoring all existing system data from the robot

Design of a controllable pitch underwater thruster system

Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution August 1993Control systems for underwater vehicles have reached the level of sophistication where they are limited by the dynamic performance of the thrust actuators. Standard fixed-pitch propellers have been shown to have very poor dynamic characteristics, particularly at low thrust levels The dynamic response of a fixed-pitch propeller is dependent upon highly non-linear transients encountered while the shaft speed approaches its steady-state value. This thesis proposes the use of a controllable pitch propeller system to address this problem. A controllable pitch propeller varies the amount of thrust produced by varying the pitch angle of the blades at a constant shaft speed. The bandwidth of this type of thrust actuator would be dependent primarily on the speed at which the pitch angle of the blades are changed. A variable pitch propeller system suitable for retrofit into an ROV is designed and built. The system is designed for maximal pitch angle bandwidth with low actuator power consumption

A conceptual design of a propulsion system for an autonomous underwater vehicle

The need for developing propulsion systems to support missions of increased endurance for autonomous underwater vehicles is investigated and a conceptual system is proposed, based on currently available technology and desired system characteristics. The investigation evaluates and ranks alternative energy sources and proposes the use of a closed Brayton cycle gas turbine power plant using a chemical energy heat source with a metallic fuel. A thruster system using electric propulsion motors and screw propellers is selected. Evaluation factors include reliability, depth independent operation, weight, endurance, quietness and efficiency. Reliability of the proposed system is analyzed and the design modified to meet proposed reliability requirements. A knowledge-based system is developed to manage the operation of the propulsion plant in an autonomous manner. A simulation system is developed using Common Lisp and the operation of the propulsion plant and its knowledge-based management system are evaluated using the simulator

Propulsion optimization for ABE, an autonomous underwater vehicle (AUV)

Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 1991The oceanographic community is moving towards unmanned autonomous vehicles to gather data and monitor scientific sites. The mission duration of these vehicles is dependent primarily on the power consumption of the propulsion system, the control system and the sensor packages. A customized propulsion thruster is designed. This includes a specialized propeller tailored to ABE and a matched motor and transmission. A non-linear lumped parameter model of the thruster is developed and experimentally verified. The model is used to predict thruster performance and compare the design thruster with other variants of propeller and motor/transmission combinations. The results showed that there is a trade-off between rapid dynamic response and power conservation. For the typical ABE trajectory, the designed thruster provides good dynamic response and the lowest power consumption of all the modelled thruster units

A Study on the Motions of Underwater Vehicle (UV) with the Umbilical Cable Effect

This thesis presents a series of analyses on the behavior of the underwater vehicle (UV) including the umbilical cable (UC) effect. The mathematical model for hydrodynamics of UV including the coupled effect of the UC is proposed. The corresponding hydrodynamic coefficients on the UV are obtained from experiments or referring related papers. With relevant hydrodynamic coefficients, the 4th-order Runge–Kutta numerical method is used to analyze motion of the UV and the dynamic configuration of the UC. The modeling performed of the UC is using the two-end boundary-value problem and it is solved by using the multi-step shooting method. Simulations on the UV including forward moving, backward, ascending, descending, sideward moving and turning motions were performed for the UC and without UC effect. The developed hydrodynamic model may serve as a useful tool to improve the performance of the UV operated with the effects of UC. The effect of currents to the UC is also taken into consideration. The present results reveal that the UC significantly affects the motion of the UV and should not be neglected in the simulation.Acknowledgement 1 Abstract 2 Contents 3 Nomenclature 6 List of Tables 9 List of Figures 10 Chapter 1 Introduction 14 1.1 Underwater vehicle 14 1.1.1 Autonomous Underwater Vehicles 15 1.1.2 Remote Operated Underwater Vehicles 16 1.2 Applications of Underwater Vehicles 17 1.3 Motivation and Contributions 18 Chapter 2 General Structure and Dynamics of UV System 20 2.1 UV Coordinate System 20 2.2 Factors Affecting an Underwater Vehicle Dynamics 21 2.2.1 Buoyancy 21 2.2.2 Hydrodynamic Damping 21 2.2.3 Stability 22 2.2.4 Coriolis 23 2.2.5 Added Mass 24 2.2.6 Environmental Forces 24 2.2.7 Pressure 24 2.3 General Design of an UV 24 2.3.1 Hull Design 24 2.3.2 Propulsion 25 2.3.3 Submerging 26 2.3.4 Electric Power 26 Chapter 3 Mathematical Model of UV 27 3.1 General Structures and Parameters of UV 27 3.2 Basic Assumptions 30 3.3 UV Kinematics 31 3.3.1 Coordinate Frames 31 3.3.2 Attitude and Euler Angles 33 3.3.3 State Space Representation of the UV 34 3.3.4 Velocity Transformation 35 3.4 UV Dynamic 36 3.4.1 Mass and Inertia Matrix 36 3.4.2 Coriolis and Centripetal Matrix 37 3.4.3 Hydrodynamic Damping Matrix 38 3.4.4 Gravitational and Buoyancy Vector 39 3.4.5 Forces and Torques Vector 40 3.4.6 Umbilical Cable Forces 40 3.5 Simplification of UV Dynamic Model 40 3.5.1 Simplifying the Mass and Inertia Matrix 41 3.5.2 Simplifying the Hydrodynamic Damping Matrix 42 3.5.3 Simplifying the Gravitational and Buoyancy Vector 43 3.6 Thruster Modeling 43 3.7 Equations of Motion 47 Chapter 4 Mathematical Model of Umbilical Cable 49 4.1 General Structure of Umbilical Cable 49 4.2 Basic Assumptions 50 4.3 Cable Modeling Approaches 50 4.4 Three Coordinate Systems 52 4.5 Forces Acting on the Cable 54 4.5.1 Weight and Buoyancy Forces 54 4.5.2 Fluid Hydrodynamic Forces 55 4.5.3 Tension Force 56 4.6 Dynamic Equations of Cable 56 4.6.1 Catenary Equations 56 4.6.2 Static Catenary Analysis 57 4.7 Solution of the Catenary in the 3-D Case 59 4.8 Spatial Variation in the Distributed Load 64 4.9 Boundary Conditions 65 4.10 Cable Effect 66 4.11 Results Simulations of Umbilical Cable 67 Chapter 5 Simulation and Discussion 71 5.1 Forward Motion 73 5.2 Backward Motion 78 5.3 Sideward Motion 82 5.4 Ascending Motion 86 5.5 Descending Motion 90 5.6 Turning Motion 94 Chapter 6 Conclusions 99 References 10